Definition
First described by Burns in 1978, party leaders were one of his five types of transactional leaders documented. Party leaders are political leaders that represent a particular group of individuals such as democrats and republicans.
Explanation
In addition to party leaders, the other transactional leaders documented by Burns included the opinion leaders, group leaders, legislative and executive leaders. Party leaders protect their own interests, and establish the expectations in the followers that their interests will be protected too. This results in the followers rallying behind the party leaders, thereby creating a larger social resource available to the politician.
Although many of the examples that Burns used for party leaders were from the U.S. democracy, corporations can also have party leaders. For example, both company and labor union representatives will bargain during contract negotiations and compromise to move from deadlocked positions. These are the typical transactions used by party leaders.